1. Field of the Invention
The present invention relates to an information processing apparatus, an information recording medium, an information processing method, and a computer program, and, more particularly to an information processing apparatus, an information recording medium, an information processing method, and a computer program for copying, under predetermined management, data recorded on a medium (an information recording medium) such as a disk.
2. Description of the Related Art
As information recording media for various contents such as movies and music, recently, a DVD (Digital Versatile Disc), a BD (Blu-ray Disc (registered trademark)), and the like are often used. Concerning most of contents such as music data and image data recorded on the information recording media, creators, distributors, and the like have copyright and distribution right. Therefore, even a user who purchases a disk is subjected to fixed limitation on use of contents recorded on the disk. For example, the user is not allowed to unlimitedly copy the disk recorded content to another medium such as a disk.
As a copy management configuration for such media stored content, there is known a copy permission processing configuration for permitting copying on condition that copy permission information is received from a management server. Specifically, processing is performed according to a sequence explained below.
A user inserts a medium such as a content storing disk into a user apparatus such as a PC or a recording and reproducing apparatus and connects the user apparatus to the management server. Thereafter, the user apparatus transmits information specified in advance such as a disk identifier (ID) to the server. After confirming propriety and the like of the received information, the server transmits copy permission information to the user apparatus. The user apparatus can start copy processing on condition that the copy permission information is received from the server.
Such a copy management configuration is called managed copy (MC). Details of the managed copy are described in, for example, JP-A-2008-98765.
On the other hand, as a standard concerning a copyright protection technique for contents, there is an AACS (Advanced Access Content System) standard. Most of contents recorded on disks such as a BD conforming to the AACS standard are recorded as encrypted contents. As a representative encryption configuration of the AACS standard, there is a configuration for sectioning contents into units and applying a different encryption key to each of the units. By adopting such an encryption configuration, it is possible to perform content use control in unit of the unit. Various kinds of strict content use control are realized.
The unit as a segmentation unit for contents is called CPS unit. An encryption key applied to encryption processing and decryption processing of each CPS unit is called CPS unit key, unit key, or title key.
Concerning the AACS standard, please refer to http://www.aacsla.com/home, http://www.aacsla.com/specifications, and the like.
When encrypted content to which a different encryption key is applied in unit of the unit is read out from a disk and copied to another medium such as a disk, processing for once decrypting the encrypted content to be copied and, thereafter, executing re-encryption conforming to a standard of a management system corresponding to the medium at a copy destination to record the content is often performed. In other words, the content is recorded as use control content on the medium at the copy destination as well.
In this case, when a content management system at the copy source (a first management system) and the content management system at the copy destination (a second management system) are different, it is necessary to once decrypt the encrypted content at the copy source and perform processing conforming to the content management system at the copy destination (the second management system), for example, re-encryption performed by using another encryption key to record the content.
In this way, in content copy processing, it is necessary to perform processing in the following sequence:
(1) readout of encrypted content from a first medium (a copy source medium);
(2) decryption processing of the encrypted content conforming to a first management system corresponding to the first medium (the copy source medium);
(3) encryption processing of the content conforming to a second management system corresponding to a second medium (a copy destination medium); and
(4) recording processing for recording the encrypted content on the second medium (the copy destination medium).
When recorded content on the first medium (the copy source medium) is the encrypted content in unit of the unit, it is necessary to specify structure units of content, sequentially acquire unit keys corresponding to the specified units, and perform decryption processing of the units.
When the copy processing is performed under the copy management on condition that the copy permission information is received from the server, the user apparatus has to apply a unit key in unit of the unit and perform decryption. However, there is no effective rule for the user apparatus to obtain information for specifying a unit. Therefore, it is difficult to smoothly execute the copy processing of encrypted content in unit of the unit.
As the content to be copied, there are contents of various types.
An example of the content is reproduction path designated content for setting a reproduction path corresponding to an information processing apparatus and causing the information processing apparatus to execute reproduction according to the reproduction path.
Another example of the content is content code applied content for verifying a reproduction sequence executed in a reproducing apparatus, executing check by applying a code (a content code) for verifying whether reproduction processing is executed according to a correct reproduction procedure, and then allowing the reproduction processing.
The reproduction path designated content is described in JP-A-2008-84445. The content code applied content is described in Japanese Patent No. 4140624.
When copy processing of the contents of the various types is performed, unless processing adapted to the content types is performed, it is difficult to perform normal copy processing.